As an issue on fuel cell vehicles, there is the problem of undergoing a reduced startability at low temperatures. In cases of fuel cell vehicles parked outdoor in the night, or under low-temperature environments such as those in cold weather districts, fuel cells may have reduced power-generating performances, involving such cases as failing to feed necessary power when starting or running. In this regard, as a countermeasure, there has been proposed a method of warming a fuel cell stack, using a heater or an exhaust fan (for instance, refer to the patent literature 1 below). This method involves issues including increased power consumed by the heater, or increased numbers of parts such as those due to addition of the exhaust fan to be dedicated for the warming. Moreover, there has been proposed a method of using discharge gases of fuel cells for heating pieces of equipment to be warmed (for instance, refer to the patent literature 2 below). Besides them, there have been proposed warming methods using heat storage materials or catalyst combustion, or the like. However, all the proposals have been accompanied by problems such as complexity of the system being a fuel cell apparatus, and an increased number of components being the parts.